Photoluminescence study of band‐gap alignment of intermixed InAsP/InGaAsP superlattices

The band‐gap alignment of InAs1−xPx/In0.53Ga0.47As1−yPy strained heterostructures fabricated by selective As–P interdiffusion in an as‐grown InP/In0.53Ga0.47As superlattice has been investigated using low‐temperature photoluminescence. Interdiffusion is performed using thermal anneals with phosphorous gas ambient. By analyzing both the energy and the integrated intensity of the superlattice photoluminescence along with their dependences on excitation intensity, it is demonstrated that the superlattice band alignment is of type I for x≳0.58 and y